Voula Papachristou has been expelled from the Greek Olympic team. Photograph: Str/AFP/Getty Images

The Greece Olympic team have expelled their triple jumper Voula Papachristou after she made a racist remark on Twitter, days before she was due to compete at London 2012.

Papachristou, 23, who was part of the 105-strong Greek team in London, had commented on the widely reported appearance of Nile-virus-carrying mosquitoes in Athens by tweeting: "With so many Africans in Greece, at least the mosquitoes of West Nile will eat homemade food." She subsequently deleted the message.

The comment provoked a furious reaction on Twitter, with responses including: "If you are serious, the Greek Olympic Team should put you on the first plane and send you back", and "Xenophobic comments from a Greek athlete in the Olympic mission are unacceptable. We are ashamed."

An announcement from the Greek Olympic Committee condemned the comment as "contrary to the values ​​and ideals of the Olympic movement".

Papachristou said in a statement: "I would like to express my heartfelt apologies for the unfortunate and tasteless joke I published on my personal Twitter account. I am very sorry and ashamed for the negative responses I triggered, since I never wanted to offend anyone, or to encroach human rights.

"My dream is connected to the Olympic Games and I could not possibly participate if I did not respect their values. Therefore, I could never believe in discrimination between human beings and races.

"I would like to apologise to all my friends and fellow athletes, who I may have insulted or shamed, the National Team, as well as the people and companies who support my athletic career. Finally, I would like to apologize to my coach and my family."

Papachristou's coach, George Pomaski, said the expulsion was unduly harsh. "It's too much, the penalty should not have been so strict. She has already apologised for her remarks.

"This is a big disappointment not only for her but for her family and for myself, and anyone involved in the Greek team."